The reason why some of us can’t drink milk

We have all grown up hearing the importance of getting the daily requirement of calcium. It promotes good bone health, which you need as a child and also as you get older. But why do some of us experience bloating and indigestion? Do you have problems digesting milk?

Lactose intolerance is the inability to digest lactose – the sugar found in milk – due to a deficiency of the enzyme lactase needed for digestion. As a result people often experience discomfort from mild intolerance, to abdominal pain, nausea, cramps and diarrhoea. Knowing this people have learned to adjust their diet and complement their calcium intake with supplements or other calcium-rich foods. More recently, there even seems to be an increasing trend of dairy-free products on the market. Have you noticed the rising number of dairy-free, soy, almond options at your local cafe?

Though this may seem like just another trend, maybe we shouldn’t so quickly dismiss this digestive problem. Historically, certain countries don’t actually consum much diary. In fact, in some Asian countries, 90 per cent of the population is lactose intolerant. So why is that Europeans can drink milk but Asian’s can’t? Have some of us developed an allergy to it or are we simply just prone to poor digestion of certain foods?

Researchers recently found evidence from DNA dating back to the Bronze Age to explain why this has happened. Apparently during this era, from approximately 3000 to 1000 BC, there was mass migration to Europe that caused a change in peoples genomes.

The Yamnaya people, sheepherders from western Russia, moved into Europe and brought with them the genetic disposition to digest cows’ milk.

Before their arrival there was only a 10 per cent tolerance of lactose in the region, the scientists found by studying the ancient DNA, and natural selection helped pass on the new gene. How cool is that?

Continued DNA sequencing is helping to provide a more accurate answer to our human development. So if you’re one of many who have suffered a lifelong intolerance to dairy, blame your non-Russian ancestors!

Tell us, do you have trouble digesting diary? When did you develop this intolerance?